In the related art, there has been known a vertical heat treatment apparatus capable of performing a batch heat treatment on a plurality of substrates such as, for example, semiconductor wafers.
As a vertical heat treatment apparatus, there has been known an apparatus including a processing container that accommodates a substrate holder for holding a plurality of substrates at a predetermined interval in the height direction, and a furnace body provided around the processing container and including a heater for heating substrates carried into the processing container. As the heater, a so-called energy saving heater having a high heat insulating performance may be used in some cases from the viewpoint of energy saving.
However, in the case of using the energy saving heater, the temperature controllability deteriorates because the furnace temperature is difficult to lower due to the high heat insulating performance. Therefore, a blower is used to forcibly cool the processing container by supplying a coolant (e.g., air) into the furnace body (see, e.g., Japanese Patent No. 5893280). By using a blower, the time for lowering the furnace temperature may be shortened. Thus, the temperature controllability is improved.